The Viral Vector Core is a critical resource for investigators both within and outside the University of Pennsylvania (UPenn) interested in the use of viral vectors for gene therapy for preclinical research with the potential to translate into the clinic. The Vector Core provides adenoviral vectors, lentiviral vectors and adeno-associated viral vectors (AAV) and offers a full range of services including cloning, DNA amplification and characterization, vector design and consultation. The Core has over a decade of experience in the production of vectors for basic research and is closely associated with one of the premier gene therapy laboratories in the country. Located in a state-of-the art facility on the UPenn campus, the Core is fully equipped with the resources, equipment and dedicated staff of professionals to carry out the objectives and aims described in this application. The Core specializes in the production and distribution of novel AAV serotype vectors developed in the Wilson laboratory at Penn, including AAVS, the Clinical Candidate serotype forthis POI. An integral part of the Core is its quality control program which is carried out by a separate Quality Control Group. Although the vectors produced by the Core are research grade, quality control assays have been developed that are relevant to clinical grade material and graded release criteria are in place which must be met before the release of any vector produced in the facility. The overally objective of the Core is to provide the participants of this POI with advanced vector technologies for preclinical studies focusing on the development of gene therapy for ornithine transcarbamylase deficiency (OTCD). The Specific Aims are as follows: (1) to produce high quality preclinical vector designed according to the needs of each project; (2) to conduct robust quality control on each vector and adhere to the release criteria established for each vector platform and (3) to conduct process and assay development relevant to the needs ofthe program project. RELEVANCE (See instructions): The Viral Vector Core provides advanced vector technologies to investigators interested in gene delivery using viral-based vectors to study disease mechanisms and develop gene therapies for genetic and metabolic diseases including urea cycle disorders.